144 



PHYSIOGRAPHY. 



[chap. 



another. Could a clean cut be made through the ground 

 in such a delta, the cut sides would expose the edges of a 

 number of beds or layers, of which the lowest must needs 

 be the oldest or earliest formed, and the uppermost the 

 youngest or latest formed ; the materials of the delta, are, in 

 fact, stratified. 



In following a river from its mouth towards its source, it is 

 generally found to be continually branching out into smaller 



Fig 35 — Delta of the Nile. 



and smaller streams, not unlike the ramifications of a tree, 

 until, at length, it is lost in a multiplicity of little rills. And, 

 in tracing a river downwards into its delta, it is found in like 

 manner that it divides and subdivides, till at last it is split 

 up into a network of channels, and reaches the sea through 

 a number of separate openings. The arrangement of 

 branches in the delta is therefore similar to that in the 



